The present invention relates to an electron probe microanalyzer (or x-ray microanalyzer) or the like which equips with a wavelength-dispersive x-ray spectrometer and an energy dispersive x-ray spectrometer and, more particularly, to a spectrum display device which is for use with such an electron probe microanalyzer and on which two kinds of x-ray spectra are displayed according to the detected signals coming from the two x-ray spectrometers.
An electron probe microanalyzer or the like incorporates both a wavelength-dispersive x-ray spectrometer as disclosed in U.S. Pat. No. 3,914,605 and an energy-dispersive x-ray spectrometer as disclosed in U.S. Pat. Nos. 4,253,154 and 4,697,080. A specimen placed in the microanalyzer is irradiated with an electron probe. Then, characteristic x-rays emanating from the specimen are detected, and an x-ray spectrum is displayed according to the result of the detection. Thus, the elements included in the specimen are identified.
These two kinds of x-ray spectrometers for detecting characteristic x-rays emitted from a specimen have different features. In particular, the wavelength-dispersive x-ray spectrometer exhibits high resolution in terms of wavelengths, but it cannot easily remove higher-order x-rays it entails. On the other hand, the spectrum from the energy-dispersive x-ray spectrometer has no higher-order x-rays, but it shows poor energy resolution. Especially, it cannot easily detect quite light elements, for example, in the range from Be (berryllium) to F (fluorine).
Accordingly, it is the common practice that x-ray spectra obtained by the two kinds of spectrometers are separately displayed on a display device to identify elements. When a wavelength spectrum derived by the wavelength-dispersive spectrometer is displayed, the operator might misidentify the included elements because of higher-order x-rays. Meanwhile, when an energy spectrum obtained by the energy-dispersive spectrometer is displayed, peaks tend to overlap due to poor energy resolution. As a result, the operator might overlook some elements included.